An action group believes that rather than making roads safer, the police road safety vans are increasing the risk to motorists on British roads.

The Dorset Speed group has compiled a database of the mobile speed cameras parked in seemingly dangerous locations including roadside verges, hard shoulders and slip lanes.

Drivers' lives are being put at risk by precariously-parked speed camera vans like this one, according to road safety group, Dorset Speed

Danger: This photo, supplied by road safety group Dorset Speed, shows a van on the side of the A35 near Poole

Campaigners from the group say that most motorists instinctively brake when they see a speed trap

It has been calling for a ban on speed cameras since the death in 2011 of motorcyclist Timothy Rowsell, 64, who crashed his bike and died after braking too hard when he saw a camera van near Bournemouth.

In the latest incident, a police vehicle was spotted parked on a concrete verge in front of a safety barrier along the Dorset Way dual carriageway in Poole, Dorset.

Ian Belchamber, from Dorset Speed, said: 'This is something that is not uncommon on our roads - police mobile speed camera vans are often spotted parked in dangerous locations.

He said everybody's immediate reaction on seeing a speed camera was to slam on the brakes, regardless of the speed they were travelling, and added: 'If something isn't done to stop it then there will be more tragic cases like that of Timothy Rowsell.'